Transcript Instrument Requirements

Mini-RF Requirements Overview
Mary Reden
NASA/GSFC SGT, Inc.
August 16-17, 2005
NASA’s Goddard Space Flight Center
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Mini-RF Overview
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Mini-RF is a NAWC/WD-provided synthetic aperture radar technology
demonstration provided to the LRO spacecraft for the purpose of
demonstrating new radar technology for future use in planetary resource
mapping.
Mini-RF is composed of the following major elements:
– Fixed planar antenna with dimensions 125 x 75 x 5.5 cm
– Electronics box with dimensions 14.2 x 20.3 x 12 cm
– Cable harnessing between the electronics box and the antenna,
and to spacecraft electrical interfaces.
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S-Omni
Antenna
Mini-RF
E-Box
Mini-RF
Antenna
Mini-RF is the second in a spiral technology development effort, preceded by
the Forerunner radar to be placed into Lunar orbit aboard the Chandrayaan-1
satellite.
Mini-RF will make a series of measurements to demonstrate enhanced
technology capabilities over the Forerunner instrument.
NASA’s Goddard Space Flight Center
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Mini-RF Block Diagram
NASA’s Goddard Space Flight Center
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LRO Requirements Document Flow
Level
1
2
2
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2
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3
3
3
3
Document Number
ESMD-RLEP-0010
431-RQMT-000004
431-RQMT-000157
431-OPS-000042
431-SPEC-000008
431-SPEC-000012
431-SPEC-000091
431-SPEC-000103
431-SPEC-000112
430-HDBK-000007
431-ICD-000152
431-ICD-000158
431-ICD-000159
431-ICD-000160
NASA’s Goddard Space Flight Center
Title
LRO Program Requirements Document
LRO Mission Requirements Document
Mini-RF Requirements and Goals Document
LRO Mission Concept of Operations
LRO Electrical Systems Specification
LRO Mechanical Systems Specification
LRO Thermal System Specification
LRO SpaceWire Specification
LRO Technical Resource Allocation Specification
Generic Instrument Performance Assurance User's Guide
Mini-RF Electrical Interface Control Document
Mini-RF Mechanical Interface Control Document
Mini-RF Thermal Interface Control Document
Mini-RF Data Interface Control Document
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Mini-RF Level 1 Requirements
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Mini-RF Level 2 requirements are defined, and are traceable to a single
Level 1 requirement:
– LRO Program Requirements Document, #ESMD-RLEP-0010
• RLEP-LRO-P160 Technology Demonstration - The LRO shall accommodate the NAWC
provided Mini-RF device in order to provide the opportunity for demonstration of this
technology in the lunar orbital environment provided it does not increase the project cost,
delay the launch date, adversely impact the achievement of full mission success, or
increase the overall risk posture of the primary mission.
NASA’s Goddard Space Flight Center
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Mini-RF Level 2 Requirements
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Key mission requirements:
– LRO Mission Requirements Document (MRD), #431-RQMT-000004
– LRO Mission Concept of Operations Document, #431-OPS-000042
– Mini-RF Requirements and Goals Document, #431-RQMT-000157
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Key performance assurance requirements:
– Generic Instrument Performance Assurance User's Guide, #430-HDBK-000007
• Tailored for Mini-RF to specifically address those areas that may adversely impact the
achievement of full mission success, increase the overall risk posture of the primary
mission, or have safety implications
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Key verification requirements:
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LRO Electrical Systems Specification, #431-SPEC-000008
LRO Mechanical Systems Specification, #431-SPEC-000012
LRO Thermal System Specification, #431-SPEC-000091
LRO SpaceWire Specification, #431-SPEC-000103
LRO Technical Resource Allocation Specification, #431-SPEC-000112
NASA’s Goddard Space Flight Center
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Mini-RF Requirements Implementation
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Implementation of the Mini-RF requirements:
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Mini-RF Spacecraft Mechanical ICD, #431-ICD-000158
Mini-RF to Spacecraft Thermal ICD, #431-ICD-000159
Mini-RF to Spacecraft Electrical ICD, #431-ICD-000152
Mini-RF to Spacecraft Data ICD, #431-ICD-000160
NASA’s Goddard Space Flight Center
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Driving Requirements on the Spacecraft
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Mechanical
– The spacecraft shall maintain a Mini-RF mass allocation of 12 kg, including margin
– The spacecraft shall mount the Mini-RF antenna such that the antenna normal is
~45-degree off-nadir, on the anti-sun side of the spacecraft
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Thermal
– The spacecraft shall provide survival heater switch service to maintain the Mini-RF
devices within the following temperature limits:
• -34 to +71 C for electronics
• -160 to +100 C for antenna
NASA’s Goddard Space Flight Center
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Driving Requirements on the Spacecraft
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Electrical
– The spacecraft shall provide 2 and 5 amp 28 v power services
– The spacecraft shall provide a SpaceWire interface directly to the Solid State
Recorder
– The spacecraft shall accommodate a data transfer rate of 8 Mbps (nominal) up to 32
Mbps (maximum) during data collections
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Operational
– The spacecraft shall provide Mini-RF with a minimum of 12, 4-minute data
collection opportunities over the LRO nominal 1-year mission
• Mini-RF desires 2 successive orbits in each of 6 modes (S/X-bands, dual/quad
polarization, mapping/zoom resolution)
• Additional data collects at the lunar poles, bi-static radar operations and off-nadir pointing
will be documented in the Concept of Operations Document as desirable targets of
opportunity
NASA’s Goddard Space Flight Center
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Mini-RF Constraints
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The Mini-RF antenna and electronics box shall be thermally isolated from the
spacecraft
Accommodation of Mini-RF on LRO shall not interfere with achievement of
full mission success, or increase the overall risk posture of the primary mission
– Mini-RF shall not interfere with LRO S/C S-band and Ka-band operations
• Mini-RF waveform and electronics shall be designed to eliminate any interference with
spacecraft S-band operations
• Impact of interference shall be minimized by limiting, if necessary, the duration of
Mini-RF collection intervals
– Mini-RF operations shall be deconflicted with LROC scenes and with the S/C
communications timeline
• Data collection orbits will be infrequent and will be chosen to accommodate LRO mission
constraints.
NASA’s Goddard Space Flight Center
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